Science Naming formulae of compounds

1. FOURWAYS HIGH
SCHOOL
NATURAL SCIENCES
GRADE 9
NAMING OF
FORMULAE OF
COMPOUNDS

2. In order to give the correct formula of a compound with the
correct ratio of elements refer back to your periodic table with
the bonding numbers:
1 2
3 4 3 2 1 0
All 2 (except silver which is
1)

3. ALSO: know the bonding numbers of your special groups:
Group Formula Bonding number
NO3 Nitrate 1
OH Hydroxide 1
NH4 Ammonium 1
SO4 Sulfate 2
CO3 Carbonate 2

4. When calcium bonds with bromine we know that the resulting
compound is called CALCIUM BROMIDE.
Ca Br
2 1
1 2
CaBr2
is the correct chemical formula for
calcium bromide!!
Write down the
symbols of the two
elements
Write down their
bonding numbers
Cross the numbers
over

5. Ca NO3
2 1
1 2
When calcium bonds with the nitrate group we know that the
resulting compound is called CALCIUM NITRATE.
Note: The whole nitrate group gets 2 as a bonding number,
and that is the reason for the brackets!!
Write down the
symbols of the two
elements/ groups
Write down their
bonding numbers
Cross the numbers
over
Ca(NO3)2 is the resulting formula!!